Artificial limb



O. H. ERICKSON oct. 11, 1927.

ARTIFICIAL LIMB 2 Sheets-Sheet 1 o Filed May 16l 1925 i i .17 9J' Patented Oct. 11, 1927.

Umfrin) STATES PATENT oFFlcE.

OTTO H. ERICKSON, OF MINNEAPOLIS, MINNESOTA.

yARTIFICIAL LIMB.

Application med May 16.1525. seriai No. 30,718.y

My invention relates to artificial legs, and

has for its object to improve the same in the several particulars hereinafternoted.

To the above end, the invention consists of Ythe novel devices and combinationsfof deextension and knee joints;

Fig. 3 is a fragmentary isometric view of the upper end portion of theshank; Y

Fig. 4 is a bottom plan view of the artitical leg; Y

Fig. 5 is a detail view with some parts sectioned substantially on the line 5 5, on an enlarged scale;

Fig. 6 is a fragmentary detail view principally in central verticalV section taken through the front portion of the shank extension and socket, on an enlarged scale; and

Fig. 7 is a fragmentary detail view show ing a slight modification of the method of attaching the heel to the foot.

rlie artificial leg illustrated is for an amputation below the knee, and of the'parts thereof, it is important to note the foot 8, shank 9, socket 10,7thigh lacer 11, and knee joints 12 connecting said socket to the thigh lacer.

The foot 8 and shank 9 are connected byv an ankle joint shell 13 havinga pair of A axially spaced circumferentiallyy extended bearing ribs 14 and which shell and ribs are mounted in seats in said foot and shank. A

leather bearing 15 is interposed between the.

foot 8 and ankle joint shell 13 and extends the full length of said shell. The' ankle joint shell 13 is secured to the shank 9 by a pair @tuut-equipped studs 16 and to the foot 8.

by a screw-threaded T stud 17 having a nut 18 mounted in a recess 19 in the bottom of a transversely extended cylindrical grease container 2O one end of which is permanently closed. Mounted 1n the other end of the grease container 20 is a grease pressure device in the form of a screw plug 21 having screw-threaded engagement therewith. This screw plug 21 has a'transverse notch adapted to VreceiveV ascrew driver'by which said screw plug may be turned. Formed in the footu8 and extending through the leather Ibearing 15 is a pair of grease ducts 22 leading fromv 'the grease container 2O to the ankle joint shell 13 at its bearing ribs'14. Obviously by screwing the screw plug 21 into the container 20, the grease therein will be forced throng the V,ducts 22 to the ankle joint.

Interposed between the foot 8y and the shank 9 forward of the ankle'v jointy is a cushion stop 23 and interposed between said foot and shank rearward of said ankle joint i is a heel spring 24 encased in a leather shell 25.

Thesole 26 of the foot 8 is held in position partly by a pair of screws 27 located near the `rear end portion' thereof, and said sole rearward of the screws 27 is loose. `The ,foot 8 is provided with a" resilient, pliable heel 28, the forward portion of `which is wedge-shaped and loosely inserted under the rear end portion of the solew26, land 'itsrear end portion is held by a T-strap 29 secured tothe foot 8. This heel 28covers the'nuty 18 and the recess 19, and access may be had to said nut by buckling the heel 28 `to vwith- 1,644,szz

draw its wedge-shape front end portion from under the sole 2G and theny moving said heel forward out of the strap 29.

Referring'fnow to the'modification shown in Fig.y 7 the heel '30 is 'identical withV the 'heel 28 with the exception lthat the same is l provided ywith one or more "dowel pins 31 inserted intojseats 32 in thefoot 8 and cemented or otherwise secured thereto. By

buckling the heel 30, the wedge-shaped forward end lportion thereof may bewithdrawn from under the sole 26 and then the heel bent i' backwardsk without removing the dowel pins 31 from their seats 32 to afford access to the nut 18. Y

One of the primary objects of my present invention is to produce a shank or other leg member and a socket therefor that have more nearly the appearance and size of the natural leg and at the same time have the required strength, weight and bearing surfaces between the leg member andr socket.

To produce a relatively thin leg member and socket, as shown, I provide the shank 9 with a'thin metallic upper extension 33 andv form on the exterior of the socket 10, upper llt) shank.

t engagement with the upper edge of the shank -Theupper shoulder 3e and upper edge portion' of the shank 'extension 33 have a `greater diameter than the shoulder 3'5 and upper edgeportion of the shank 9 so that thesocket l0 telescopes into the shank 9 and i'itfsfektension 33.

Toseourely attach the shank extension 33 to the ishank'f), said extension hasformed .in *its lower edge portion, a plurality1 of notches 36 which are circumferentially spaced to leave'y a plurality of circumferentially spaced wide prongs 37 therebetween. The loweredge portion of theshank extension 33 and its pro'ngs" 37 are telescoped onto the shank 9 and'the outer face of said shank is `,ez'fternally reduced at'38 to receive said'eX- tension and prongs to countersink the same intro the shank 9 so that the outer faces of s aidektension yand prongs are flush with the exteriorof said'shankfr In addition to the interlocking engagement of the prongs 37 vvfitlrtheI shank 9:, the shank extension 33 is furtherl securedy to the shank 9 by a plurality l of rivets l39,inserted through each prong 37 andthe Shank, 9.

l "Applied,A around the shank 9 is a shell 40,

preferablyL fraw hi1de,'an^d which shell enf tends upwardonto'the shank extension 33 toa [point above itsv prongs 37 and covers the joint between the4 shank 9 and its extension 33y andreinforces the same. e

Appliedaroundthe upper end portion of the shellA $0 is a'band of leatherlll or other suitable material which 4extends onto the "shankfextension '33 slightly above the upper edge yof the-shank 39 and cover the same, and further reinforces the Joint between the 1,. An artificial leg member, a thin metallic upper 'extension telescoped onto said leg member [and rigidly secured thereto, an outer covering shell applied around said leg member and extended up to said upper extension, av band applied around the upper portion of the outer shell of said leg member and .around the lower portion of said metallic upper extension and secured to both thereof :and covering the joint therebetween and re inforcing the same.

'2. "Airar'tificifal" leg member Vhaving an eX- ternally reduced upper end portion and depending circumferentially space-d grooves, an upper extension telescoped "onto the reduced upper endl portion of the leg `member and having ldepend-ing circumferenti-ally spaced prongs extending' into said grooves, anda "socket" mounted `in the leg member and its extension.

'The' structure deli-ned in claim 2 in further combination withan o'u'tershell applied 'tothe leg member and overlapping said vupper extension and extending to a point above its prongs. 1

' 4. The structure delinedfin claim 2in further combination Vwith a band applied around theleg member and its extension at said prongs and extending above and below the same. v

5. Anartili'cial leg member having a rigid movable socket, said member having upper and lower circumferentially extended shoulders, and said socket having upper andv lower circumferentially extended shoulders engaging, respectively, the upper and lower shoulders of theV leg member and supporting' the socket therefrom,'the lower shoulder on the socket being above the lower end thereof and the,y lower end portion of the socket below its lower shoulder being tel-escoped into the leg section. Y

6. An artificial leg memberA having an Vupper extension applied thereto, and a socket having upper and lower circumferentially extended shoulders engaging, respectively, 'the upper end of said extension andthe upper endv of said leg member andY supporting the socket therefrom, the lower shoulder onthe socket being above the lower end thereof and the lower end portion of the socket below its lower shoulder beingv telescoped into the legvmember.

In testimony whereof I aliik my signature.

' OTTO H. ERICKSON. 

